[PATCH 5.17 0160/1126] crypto: rsa-pkcs1pad - only allow with rsa

Greg Kroah-Hartman
2022-04-05T07:47:40Z

From: Eric Biggers <ebiggers@google.com>

commit 9b30430ea356f237945e52f8a3a42158877bd5a9 upstream.

The pkcs1pad template can be instantiated with an arbitrary akcipher
algorithm, which doesn't make sense; it is specifically an RSA padding
scheme. Make it check that the underlying algorithm really is RSA.

Fixes: 3d5b1ecdea6f ("crypto: rsa - RSA padding algorithm")
Cc: <stable@vger.kernel.org> # v4.5+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
crypto/rsa-pkcs1pad.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -621,6 +621,11 @@ static int pkcs1pad_create(struct crypto

rsa_alg = crypto_spawn_akcipher_alg(&ctx->spawn);

+ if (strcmp(rsa_alg->base.cra_name, "rsa") != 0) {
+ err = -EINVAL;
+ goto err_free_inst;
+ }
+
err = -ENAMETOOLONG;
hash_name = crypto_attr_alg_name(tb[2]);
if (IS_ERR(hash_name)) {